Decision-Making of Evacuation from Tohoku Tsunami in 2011

Abstract

Tohoku tsunami occurred at March, 11, 2011. During this even, tsunami warning was issued to all regions among Pacific Coast, and all Mass media broadcasted about tsunamis. This situation was similar to Chile Tsunami in 2010. In this paper, we grasp behaviors of residents at Tohoku Tsunami occurrence, and compare evacuation behavior form Tohoku tsunami with Chile Tsunami. And we develop the decision making of tsunami evacuation model considering scale of tremor, height of tsunami in expectation by tsunami warning and kind of evacuation order. Therefore I carried out a questionnaire survey for the residents who lived in the large area of the Pacific coast.

As the result, the factor that affected residents' evacuation behavior the most was “evacuation order”. Most of residents who got the evacuation order have evacuated form tsunamis. In addition, tsunami warning, 3 meters height of tsunami in expectation, cannot urge residents to evacuate from tsunamis. On the other hand, the rates of residents who evacuated from Chile Tsunami but did not evacuate from Tohoku Tsunami were approximately 60%. One of the reasons was that these residents remember that almost regions were attacked smaller tsunamis than expectation at Chile Tsunami in 2010.